My Outlook 2003 has a little problem that niggles me.
It follows a similar pattern..I try to do something simple (eg. this morning it was moving emails) and the hourglass comes up, the screen goes white, and Outlook stops responding. I'll leave it a while but I usually end up having to reboot, then it says Outlook wasn't closed properly so it takes 10 mins or more to check for faults etc, then eventually it all settles down and all is well.
My email is pretty large - just over a 1Gb is size. I am pretty sure that this must have something to do with it.